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標題: | 鄰近耦合微帶洩漏模天線陣列與半寬度微帶洩漏模天線設計 Design of Proximity-Coupled Microstrip Leaky Mode Array and Half-Width Microstrip Leaky Mode Antennas |
作者: | Guang-Fu Cheng 鄭光甫 |
指導教授: | 莊晴光 |
關鍵字: | 天線,洩漏模, Antenna,Leaky mode, |
出版年 : | 2013 |
學位: | 博士 |
摘要: | 本論文研究包含一鄰近耦合微帶漏模天線陣列,一半微帶線寬度之雙漏模天線,與一反向激發之互耦合半微帶線寬度之漏模天線。
在鄰近耦合微帶漏模天線陣列的研究中,本論文探討短於一真空波長的微帶線之漏模輻射特性並利用鄰近耦合激發方式將其設計為天線陣列單元。同時並設計一天線陣列的匹配負載單元,其負載單元提供了阻抗匹配功能進而使得天線陣列匹配頻寬增加,並抑制在負載端因反射造成的背面旁波束。研究中並建立天線單元的等校傳輸線模型用以預測陣列之輻射效率的等效傳輸線模型。天線陣列在10.525 GHz其增益量測值高達19.1 dBi。而量測的輻射效率在10.525 GHz達到87 %,最高在10.325 GHz可達到 91%。 在半微帶線寬度之雙漏模天線研究中,首先提出一波導結構可存在雙第一高階模(EH1 mode),並利用此波導結構設計出一個具有雙第一高階模之漏模天線。所提出的波導結構包含了兩個不同寬度之半寬度微帶線,因而此波導結構存在兩個第一高階模態,而每一個高階模態的操作頻率可以藉由微帶線的寬度做獨立設計。在模擬與量測結果中兩個模態的隔離度高達20 dB以上。 最後是一個反向激發的互耦合的半寬度互耦合微帶漏模天線研究。首先提出了一個互耦合的半寬度微帶線結構,並研究存在此波導結構之奇、偶模的特性。從研究中發現奇模在操作頻寬與輻射特性皆優於偶模,並實作一個反向激發、互耦合、奇模的半寬度漏模天線。包括饋入結構的天線尺寸為1λ0 ×3.6λ0。最高的天線增益量測值為11.6 dBi,相較於中心頻率有15 %的頻寬,增益平坦度為2.4 dB,輸入反射損耗高於10 dB。 This dissertation presents a proximity-coupled microstrip EH1 mode array, a dual EH1 mode half-width microstrip antenna, and a differentially excited coupled half-width microstrip leaky EH1 mode antenna. In the design of the proximity-coupled microstrip EH1 mode array, the radiation characteristics of the EH1 mode microstrip line with a length shorter than one free space wavelength are investigated and designed as an array element. The matched radiating-element load is also proposed to provide the wider bandwidth of input impedance matching and the back lobe suppression. Furthermore, the equivalent transmission line model of array element is reported to predict the radiation efficiency of the array. The measured results of the antenna gain and the radiation efficiency are 19.1 dBi and 87% at 10.525 GHz, and the measured maximum radiation efficiency is 91% at 10.325 GHz. In the studies of dual EH1 mode half-width microstrip antenna design, the guided-wave structure support dual EH1 mode is proposed. A prototype design of dual EH1 mode antenna is also provided. The proposed guided-wave structure consists of two different half-width microstrip lines. Each half-width microstrip line supports an EH1 mode. The operation frequency of these two leaky modes can be designed independently. The isolation of two leaky modes is better than 20 dB over both leaky modes operation bands in simulated and measured results. Finally, a differentially excited coupled half-width microstrip leaky EH1 mode antenna is presented. The guided-wave structure of coupled half-width microstrip lines are proposed and investigated, showing two leaky modes in the form of even- and odd-symmetry, respectively. Rigorous studies show that the odd-leaky-mode iv outperforms the even-mode approach in radiation patterns and bandwidth. Following the rigorous investigation of the modal characteristics of the coupled half-width EH1 mode guided structure, a differentially fed, coupled, odd-leaky-mode, half-width, antenna design of size 1λ0 by 3.6λ0 (including the feed) is reported, showing measured maximum antenna gain of 11.6 dBi, 15% fractional bandwidth, gain flatness of 2.4 dB variation, and input return loss greater than 10 dB. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/58864 |
全文授權: | 有償授權 |
顯示於系所單位: | 電信工程學研究所 |
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